Bird Flu Could Spread Beyond Asia

KUALA LUMPUR, Malaysia -- Migratory birds infected with avian influenza could spread the deadly virus far beyond its stronghold in Asia, thwarting even the strictest quarantine measures on the ground, scientists report in the journals Nature and Science.

The findings offer further scientific grounding for what global health officials have warned for some time: that bird flu might be able to travel outside the population of domesticated fowl that so far have been its primary host. Tens of millions of chickens and ducks in...